Enhanced Thermoelectric Performance in Black Phosphorene via Tunable Interlayer Twist

Abstract

Twist‐angle two‐dimensional (2D) systems are attractive in their exotic and tunable properties by the formation of the moiré superlattices, allowing easy access to manipulating intrinsic electrical and thermal properties. Here, the angle‐dependent thermoelectric properties of twisted bilayer black phosphorene (tbBP) by first‐principles calculations are reported. The simulations show that significantly enhanced Seebeck coefficient and power factor can be achieved in p‐type tbBP due to merging of the multi‐valley electronic states and flat moiré bands. Moreover, the twisted layers bring in a strong anharmonic phonon scattering and thus very low lattice thermal conductivity of 4.51 W m−1 K−1 at 300 K. Consequently, a maximal ZT value can be achieved in p‐type 10.11° tbBP along the armchair direction up to 0.57 and 1.06 at 300 and 500 K, respectively. The room‐temperature ZT value along the zigzag direction is also significantly increased by almost 40 times compared to pristine BP when the twist angle is close to 70.68°. This work demonstrates a platform to manipulate thermoelectric performance in 2D materials by creating moiré patterns, leading tbBP as a promising eco‐friendly candidate for thermoelectric applications.

Review of phonons in moiré superlattices

“…The coupling of the two graphene layers in tBLGs varies strongly with the twist angle. For the large twist angle, the layers are essentially decoupled at low temperatures, but get effectively re-coupled at higher temperatures when the interlayer phonons drive cross-plane electrical transport through strong electron-phonon scattering [36] . Mahapatra et al found a novel phonon-drag effect driving thermopower in tBLG, which is related to the twist angle [26] .…”

Small twist, big miracle—recent progress in the fabrication of twisted 2D materials

“…Specifically, tbBP with a twist angle of 10.11° exhibits a high ZT value of 1.06 along the armchair direction at 500 K, and the room-temperature ZT value along the zigzag direction is over 40 times greater than that of pure BP when the twist angle is close to 70.68°, indicating that the rotation angle plays a key role in regulating the thermoelectric properties of 2D materials. 35 However, BP has poor stability in air and strong adhesion to PDMS, which poses a challenge for the preparation of tbBP by traditional wet or dry transfer. Recently, Fang and workers 36 presented a PC-film-based transfer method to fabricate tbBP with rotation angles of 7°, 50°, 75°, 80° and 90°.…”

“…[32][33][34] The introduction of twist angles is expected to offer a novel strategy for adjusting the physical properties of 2D materials. [35][36][37][38][39] The twisted structure is formed by stacking two or more adjacent layers at a certain angle, accompanied by a moire ´pattern. In the field of controllable preparation of twisted 2D materials, the research focus revolves around developing techniques and methodologies to precisely manipulate and control the twist angles.…”

“…32–34 The introduction of twist angles is expected to offer a novel strategy for adjusting the physical properties of 2D materials. 35–39…”

Adsorption properties of black phosphorene for actinides U, Th, and Pu: A first‐principles study

“…Since the first report in the literature on the exfoliation of BP by Zhang et al [12], BP has received also wide attention due to its unique electronic and optoelectronic properties. Particularly, BP possesses layer-number-tunable direct bandgap (0.31-2.0 eV) [13], elevated hole mobility ($1000 cm 2 V À1 s À1 ) [14], enhanced thermo-electric and photothermal response [15][16][17], and exceptional anisotropic mechanical and photo-electronic properties [18,19]. These properties render BP a promising material for a variety of applications, such as fieldeffect transistors [12], optoelectronic [14] and spintronic [20] devices, Li-and Na-ion batteries [21,22], solar cells [23], gas sensors [24,25], catalytic water splitting devices [26,27], photothermal therapy of tumors [28], and photodynamic therapy of pathogenic bacteria [29].…”